On an infusion solution route for performing solution infusion or blood collection, etc., there is typically provided a medical connector that makes it possible to connect a male connector such as a luer tip of a syringe tip, etc., in order to perform coinjection of a drug solution or perform collection of a biological fluid using this infusion solution route. For example, a three way stopcock widely used as a medical connector makes it possible to do coinjection of a drug solution using the already formed infusion solution route by forming an infusion solution route of a drip infusion or the like using a pair of the three aperture parts, permitting a connection of a male connector to the remaining one aperture part.
As one type of known medical connectors, Patent Document 1 (JP-A-2-502976) and Patent Document 2 (JP-A-2004-237133) disclose the so-called split septum type, for example. A split septum type medical connector is equipped with a disk shaped valve element at the aperture part, and by pressing and opening the slit by directly inserting the tip part of the male connector in the valve element slit, it is possible to have communication between the infusion solution route and the interior of the male connector.